Filter arm



FIG. 1 is a front, right, top perspective view of a filter arm showing my new design;

FIG. 2 is a back, left, top perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left view thereof;

FIG. 6 is a right view thereof;

FIG. 7 is a top view thereof;

FIG. 8 is a bottom view thereof;

FIG. 9 is a use state diagram;

FIG. 10 is another use state diagram; and,

FIG. 11 is a third use state diagram.

The broken lines shown on the drawings depict portions of the filter arm that form no part of the claimed design. 

CLAIM The ornamental design for a filter arm, as shown and described. 